import 'package:flutter/material.dart';

main() => runApp(Myapp());

class Myapp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      //Android多应用切换时显示的标题
        title: "Hello Wrold",
        home: Scaffold(
          appBar: AppBar(
            title: Text("标题"),
          ),
          body: ContentWidget(),
        )
    );
  }
}

class ContentWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Center(
      child: Text(
        "Hello World",
        textDirection: TextDirection.ltr,
        style: TextStyle(fontSize: 36),
      ),
    );
  }
}
